Why is understanding progressive sanctification important for Christians?

Progressive sanctification, as understood in a Reformed context, acknowledges that while believers are set apart for holiness at the moment of their justification, they engage in a lifelong process of becoming more like Christ. This concept is rooted in Scriptures such as 1 Thessalonians 4:3, which states that 'this is the will of God, your sanctification.' However, it's crucial to recognize that this growth does not stem from human effort alone but is a result of the Holy Spirit’s work within us, as seen in Galatians 5:22-23, where the fruit of the Spirit is described. Understanding progressive sanctification helps Christians manage their expectations and recognize the struggle between the old and new natures while learning to rely on Christ alone for holiness.